"Science fiction writers, I am sorry to say, really do not know anything. We can't talk about science, because our knowledge of it is limited and unofficial, and usually our fiction is dreadful."
- Philip K. Dick

When you've gone back in time, snatched people from an aircraft that will crash in minutes, and want to obtain physical duplicates ("wimps") that are so close to the original that the difference can't be detected, and then send them back to the crashing aircraft, you'll need one of these.

There was no way to get a grip on anything (that's why they call it frictionless). I slid through a series of chutes and onto a flat surface coated with a sheet of plastic that clung to my skin. It all happened so fast I never did understand the sequence. At some point mechanical hands removed my pants and I found myself wrapped in a tight cocoon of clear plastic. I was straitjacketed, arms at my sides, feet together.

I was tumbled in a blue light. It was frightening, even to me, and I knew what was happening. My body was being studied in minute detail, from the bones outward. The process took two seconds. I was cataloged out to eighty decimal places and the Big Computer began thumbing through its card file of wimps looking for the best match. That took about a picosecond.